Today I visited three 4^th grade classes at Lynnwood Elementary School in Schenectady (Guilderland Central School District). We were ornithologists studying owls. As part of our class we dissected owl pellets to learn about what their preferred prey is. Here is what we found.

Mrs. Janssen’s class dissected 10 pellets which contained the bones of 30 mice, 7 shrews, 1 mole and 2 birds.

Mrs. Follonsbee’s with several students from Mr. Miller’s class dissected 13 pellets which contained the bones of 38 mice, 1 shrew, 0 moles and 0 birds.

Mrs. Romano’s class with several students from Mr. Miller’s class dissected 14 pellets which contained the bones of 43 mice, 1 shrew, 0 moles and 0 birds.

A total of 37 pellets were dissected revealing the remains of 111 mice, 9 shrews, 1 mole and 2 birds. As a way of illustrating what a hypothesis is I told them that I had researched what Barn Owls eat and had hypothesized that their most favored food was rodents, such as mice. Shrews were a second favored prey and moles and birds were tied for third. Our findings would seem to support this hypothesis.

In our wrap up discussion I mentioned that there seemed to be a larger than usual number of prey per owl pellet. I speculated that this might be due to the large number of smaller mice found in the pellets. We could see this size difference when comparing skulls, jaw and hip bones. We wondered whether this might reflect the fact that at this time of year there might be many more rodent nests which the owls might find by listening to the squeaks of the young, hence the finding of smaller sized bones of young mice. An owl eating 4 or 5 small young mice might get as full as an owl eating 2 or 3 full grown mice. If we compare the average number of prey animals per pellet to the findings of pellets at a different time of the year we might find evidence supporting this.

The average number of animals per pellet with the Lynnwood students was 3.3 animals per pellet.

We can compare this to the findings from four 4^th grade classes at Leptondale Elementary School in Wallkill (see previous post). These were pellets were collected approximately one month earlier. At Leptondale there were 40 pellets dissected. These contained the bones of 122 mice, 3 shrews, 1 mole and 2 birds. This gives an average of 3.2 prey per pellet. That is not much different than the average found at Lynnwood, perhaps we need to look at owl pellets found even earlier in the year.

Let’s look at pellets collected in mid-winter. I visited the Nazareth Intermediate School in Nazareth, PA in January (see previous post in the blog archive). Working with 14 4^th grade classes we dissected 168 pellets and found 335 mice, 45 shrews, 20 moles and 6 birds for an average of 2.42 prey per pellet. If we look at what Lynnwood students found in March of 2010 there were 111 mice, 5 shrew, 1 mole and 0 birds in 41 pellets for an average of 2.9 prey per pellet.

There does indeed seem to be a difference in the number of prey eaten per pellet at different times of the year. It also seems that there might be a difference in the number of shrew and moles taken at different times of the year. Look over other owl pellets studies that I have done with other schools at different times of the year in my blog archives.